The basic rules of Dungeons & Dragons.
Dungeons & Dragons runs on a handful of mechanics, repeated session after session. A twenty-sided die, a modifier, a number to hit: everything else is a variation on that same gesture, from picking a lock to duelling a dragon.
Here are those rules gathered in one place, in the order they actually come up at the table. The d20 and the difficulty class, the six ability scores, the three rolls you will make over and over, how a combat turn plays out, hit points and resting.
The rule that governs everything.
Every action with an uncertain outcome is settled the same way: a twenty-sided die, a modifier added to the result, and a number to reach. That number is the difficulty class, or DC. Count ten for an ordinary action, fifteen when the situation pushes back, twenty when it takes a feat of skill. Matching the number is enough, beating it by a mile changes nothing.
The modifier comes from the relevant ability score: a score of 10 gives nothing, every two points above that add one, so a score of 20 is worth plus five. On top of that sits the proficiency bonus, plus two at first level, whenever the character is trained in what they are attempting. One total, one number, nothing else to remember: the whole system follows from there.
The six ability scores.
It sets melee damage, what you can carry and which doors you break down. Fighters, barbarians and paladins depend on it directly.
The most useful of the six: ranged attacks, armour class, initiative and stealth. A rogue without dexterity does not exist.
It adds hit points at every level and saves your concentration on spells. No class can afford to neglect it.
It covers recall, searching a library and working out a mechanism. It is the wizard's spellcasting ability.
Spotting what others miss, sensing a lie, resisting fear. Wisdom saving throws are among the most common in the game.
Not beauty but force of presence: persuading, intimidating, lying. Bard, sorcerer, warlock and paladin cast their spells with it.
The rolls you will make.
A d20, plus the ability modifier, against a difficulty class set by the game master. Ten is easy, fifteen takes real talent.
Same die, but the world is acting on you: a trap, a breath weapon, a spell. Each class is proficient in only two saves.
A d20 plus proficiency and ability, compared to armour class. A natural twenty always hits and doubles the damage dice.
It starts at plus two and climbs to plus six at level 17. It applies only where your character is trained, and never twice.
You have high ground, the target is blinded, an ally helps: two dice, keep the higher. It is worth about plus five, with nothing to calculate.
Shooting in the dark, meleeing from the ground, acting while poisoned. Advantage and disadvantage cancel out, no matter how many of each.
The combat turn.
Combat cuts time into six-second rounds. Everyone rolls initiative, a plain Dexterity check, and the resulting order holds for the whole fight. On their turn, a character gets three things: movement equal to their speed, one action, and sometimes a bonus action if one of their features grants it.
The action covers almost everything: attack, cast a spell, dash, hide, help an ally, disengage. Outside their turn, everyone keeps one reaction, only one per round, most often the opportunity attack against an enemy walking away. An attack hits when the roll matches or beats the target's armour class, the number measuring how hard they are to reach.
Damage, healing and death.
Every character has hit points, a pool that drops when they take damage and climbs back when they are healed. Damage is rolled with the weapon's or spell's die, plus the same modifier as the attack. As long as that pool is not empty, a wounded character acts exactly like an untouched one.
At zero hit points they fall unconscious and roll a death saving throw on each of their turns: three successes stabilise them, three failures kill them. An ally healing them, even by a single point, puts them straight back on their feet. After that, a one-hour short rest returns part of the hit points, an eight-hour long rest returns them all.
The rules people get wrong.
If the action is possible and nothing opposes it, it simply succeeds. Roll only when failure would change something in the scene.
A natural twenty only matters on attack rolls. On an ability check or a saving throw it is just a twenty.
Three sources of advantage on one roll still give a single advantage. Two dice at most, never three.
Nothing forces you to spend all your movement at once: you can step in, attack, then step back. Many tables miss this for months.
One reaction per round, refreshed on your turn: opportunity attack, counterspell, shield. Never using it wastes a free action every round.
One long rest per twenty four hours, eight hours of which six asleep. A short rest takes an hour and does not use up the long one.
Applying the rules online.
Tracking hit points, initiative order and everyone's modifiers on a corner of the table ends up demanding more attention than the scene itself. The game master spends the evening recalculating instead of narrating, and the players wait.
Tomeus gathers the sheets, the dice roller, the backdrop and the music in a single window. You create the game, send the link, and your players arrive with their character in front of them, nothing to install and nothing written on a scrap of paper that goes missing.
Go further with Dungeons & Dragons.
How to Start Playing Dungeons & Dragons
Free basic rules, dice, character creation and a first session: the complete guide to start playing Dungeons & Dragons, around a table or online.
The Lore of Dungeons & Dragons
The multiverse and its planes, the great worlds, the peoples, the pantheons and the dragons: D&D lore explained, and how to use it at your table.
The Classes of Dungeons & Dragons
The twelve D&D classes explained: barbarian, fighter, rogue, cleric, wizard and the rest, their subclasses, and how to pick yours as a beginner.
The Bestiary of Dungeons & Dragons
The monsters of D&D explained: reading a stat block, the creature types, challenge rating, and how to build an encounter that works at your table.
Go further with tabletop RPGs.
How to Play a Tabletop RPG: the Beginner's Guide
How a session unfolds, what the game master does, dice, character sheets and how to play a tabletop RPG online. A complete guide for beginners.
How to Prepare a Tabletop RPG Campaign
Setting, central stake, factions, NPCs and per-session prep: the method to build a tabletop RPG campaign without writing everything in advance.
The Best Tabletop RPGs for Beginners
Dungeons & Dragons, Call of Cthulhu, Alien, Monster of the Week: six easy tabletop RPGs for a first session, and how to pick the right one.
How to Create a Tabletop RPG Character
Concept, class, ability scores, skills, backstory and bonds: the full method to create a tabletop RPG character who will carry a whole campaign.
Frequently asked questions.
Where can you find the D&D basic rules for free?
The publisher releases a free basic rules document online. It holds the complete system, a few species and four classes playable all the way to level twenty. That is plenty for several months of play. The Player's Handbook mainly adds more options, not a different system.
Can you change the rules at your own table?
Yes, and almost every table does. The book says so outright: when a rule is missing or gets in the way of the scene, the game master calls it. The one precaution is to announce those house rules to the group, so nobody builds a character around a rule that will not apply.
What changed between the 2014 and 2024 rules?
The foundation does not move: the d20, the difficulty class, the six ability scores, armour class, hit points. The 2024 revision reworks species, backgrounds and some class features. Both versions sit at the same table without trouble, as long as the group names one of them as the reference for disputed points.